My phaser game has a player class which is a square. However there is a trailing little red square that follows the players movements. I have tried everything I can to remove it, however I can’t get rid of it or figure out what it is. 
This is strange. Can you provide some of your code? For better understanding of your problem you can also provide info about your enviroment (like phaser 2 version, browser you are using etc)
Try to remove elements until it disappears, then you can pinpoint where it is coming from, or ye as suggested share some code.